1. Technical Field
The present invention is related to a display device and a fabricating method thereof, and particularly to an electro-phoretic display device and a fabricating method thereof.
2. Related Art
With the technology advances of flat panel displays, more and more electronic products, in particular, portable electronic products such as mobile phones, e-book readers, digital cameras, and personal digital assistants (PDA), etc., are equipped with flat panel monitors. With the trend of portable electronic devices towards lighter weight and thinner thickness, displays used for portable electronic device should also have features of light weight and thin thickness.
As mentioned above, since flexible displays not only have advantages of light weight and thin thickness, but also have advantages of flexibility and anti-impact, manufacture of flexible displays becomes an important trend in future development. Currently, commonly available flexible displays include electro-phoretic display devices (EPD), which utilize electric field to control the distribution of charged particles so as to change the reflectivity of a display area, thereby displaying image. Based on the principle of displays, electro-phoretic display devices have characteristics of bistability and need no extra light source, thus in line with requirements of modern technology that flexible displays should also have the feature of highly energy-saving.
FIG. 1 is a cross sectional view of a conventional electro-phoretic display device. Referring to FIG. 1, the electro-phoretic display device 100 includes a first substrate 110, an active elements array 120, a driving circuit 130, a conductive flexible board 140, an elector-phoretic display layer 150, a second substrate 160, a sealant 170, and a driving chip 190. The active elements array 120 and the driving circuit 130 are disposed on the first substrate 110, and the electro-phoretic layer 150 is disposed on the active elements array 120. The driving chip 190 and the conductive flexible board 140 are disposed on the driving circuit 130. In addition, the driving chip 190 is electrically connected to the active elements array 120 via the driving circuit 130, and also electrically connected to a printed circuit board (PCB) 180 via the conductive flexible board 140. The second substrate 160 is disposed on the electro-phoretic display layer 150 and the sealant 170 is formed on the driving circuit 130. The sealant 170, on the one hand, protects the driving circuit 130, and on the other hand, seals the electro-phoretic display layer 150 between the second substrate 160 and the first substrate 110 to prevent the electro-phoretic display device 100 from damages resulted from ambient air or steam infiltration.
However, if the polymerization time is not accurately controlled during the process of forming sealant 170, then the obtained sealant 170 can not effectually protect the driving circuit 130 from corrosion by outer environments due to incomplete polymerization. In addition, the sealant 170 is disposed adjacent to the electro-phoretic display layer 150, thus when ambient temperature of the electro-phoretic display device 100 changes, the difference of thermal expansion coefficient between the sealant 170 and the electro-phoretic layer 150 will lead different thermal stress to the first substrate 110 and the driving circuit 130. Then, the sealant layer 170 may break, or the driving circuit 130 may be damaged.